Rear view mirror containing a fluid light controlling medium



ARCH KUUM :j b U Z U Feb. 8, 1966 G. E. PLATzER,JR., ETAL K 3,233,515

REAR VEIW MIRROR CONTAINING A FLUID LIGHT CONTROLLING MEDIUM Filed Dec. 1, 1961 j M? mi 2 CM" 6 M4 M I 72 A* J j J Mz /4 if MJ f4 j J' /M //4\ I i 4g] fa f /4 f4 /24 l /jj /27 D W mm,

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United States Patent O REAR VIEW MIRROR CGNTAINING A FLUID LIGHT CONTROLLING MEDIUM George E. Platzer. Jr., birmingham, Dwight Maxwell Teague, Grosse Pointe Farms, and Harry G. Ross, Jr., Detroit, Mich., assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware Filed Dec. 1, 1961, Ser. No. 156,405

7 Claims. (Cl. 88-77) The present invention relates generally to mirrors containing a fluid light controlling medium. It especially relates to improvements in a two-position or day-night rear view mirror such as described and claimed in the concurrently filed application f George E. Platzer, Jr. and Leonard P. Gau, entitled Rear View Mirror, Serial No. 156,404, comprising an enclosure including a transparent window and a mirror movable relative to the window and between which fluid contained in the enclosure may provide an opaque screen to inhibit light reflections from the mirror under certain conditions of operation and permit light reflection under others.

In the said Platzer et al. application there is disclosed among other forms of mirror structures one providing an enclosure that comprises a metallic frame, a transparent glass plate forming a `window for the enclosure and in fluid sealing relation to one side of the frame through a gasket or O-ring type of seal, a diaphragm type of fluid retaining wall for the enclosure made of elastomeric material and having a peripheral portion in abutment with the opposite side of the metallic frame from the glass window and to which frame it is held by a cover plate and a retaining ring which also maintains the window plate in position with respect to the frame. In this structure the body portion of the diaphragm is provided with a central lip-like aperture defined by a forwardly extending and outwardly turned wall which is spaced from the main body portion and secured to the movable mirror of the device. The diaphragm together with the window plate and frame provide a fluid chamber for receiving the fluid control medium. This structure also includes resilient m-eans for biasing the reflector plate to a forward or day position in juxtaposition to the window and against stop means provided between the window and the reflector such that in the forward position of the reflector a thin film of the fluid medium remains between the reflector and window in this position. Actuating means are secured to the rear of the reflector plate through the diaphragm opening. It is operable for moving the reflector rearwardly to its night or extinct position. During this movement of the reflector fluid is pumped thereby forwardly of the chamber around the passage created between the edge of the reflector and the metal frame to fill the increased space between it and the window. As there described the diaphragm not only serves as a wall of the fluid chamber but also as a means for facilitating changes in volume of the fluid medium caused by changes in temperature.

The described structure, while novel in its character, presents problems of assembly, of filling the fluid chamber with fluid and in particular of sealing the joints made by the several parts to keep the fluid from seeping out of or evaporating from the chamber. Moreover, the structure presents broblems of securing the reflector actuating means to the glass reflector. In connection with these problems, it has been found best to fill the fluid chamber with fluid by assembling the parts of the mirror structure submerged in a fluid bath containing the fluid medium and of either temporarily or finally sealing the chamber with the assembly still submerged. Such pro- 3,233,515 Patented Feb. 8, 1966 lCC cedure requires the handling of a plurality of independent parts, to wit: the window, the window seal, the diaphragm, the reflector, the end support plate and the retaining ring, all while submerged in the fluid. To assemble and clamp these pieces all together to produce a fluid type closure before removing the assembly from the fluid bath after being sure that sufficient fluid is in the chamber and all air displaced therefrom requires considerable ingeniuty and is quite diflicult at best. Furthermore, since the reflector member is usually a glass plate provided with a mirrored surface, a problem of attachment of metal to glass is also encountered.

The present invention aims to avoid the foregoing problems of assembly and fluid sealing and if desired to eliminate the glass to metal bond. It may be accomplished by preforming the diaphragm member of a pan shape whereby it may receive and enclose the mirror frame and simultaneously provide a seal for the window plate. Such a construction may also simultaneously provide an intermediate layer through which the actuating member for the reflector may be secured thereto. In assembling the various elements of the mirror structure it will be recognized that the diaphragm may be assembled to the reflector and frame outside the fluid bath for the mirror frame provides a rigid holder for the assembly and all three parts form an integral arrangement in which no shifting of one with respect to the other can take place when this sub-assembly is submerged in the fluid. This may be contrasted with the handling of a flexible diaphragm that is loose with respect to the frame and that must be brought into a face-to-face sealing arrangement therewith after submerging in the fluid as is necessary in the structure described in said concurrently filed application. With the construction in the present invention, it is a simple matter to assemble the window plate against the sealing face of the diaphragm while submerged and position the support plate and retaining ring if desired while submerged in the fluid or provide alternative means for clamping the window and the cover plate in position while submerged and thereafter assembling the retaining ring outside of the fluid.

Accordingly the principal object of the present invention is to provide a mirror construction containing a light controlling fluid medium in which a single member provides the means for facilitating changes in volume of the fluid without resultant cavitation or stressing of the mirror parts and which member also provides the means of sealing the structure to prevent seepage or evaporation of fluid.

Another object is to provide a mirror construction as in the preceding object wherein the stated member is a diaphragm of elastomeric material such as a synthetic butadiene-acrylonitrile rubber which is so constructed that only a single fluid seal is required in the mirror assembly.

A further object is to provide a mirror construction as in the preceding objects wherein the stated member comprises a preformed shallow pan shaped element of elastomeric material having resilient shape retaining properties and which is adapted to receive the frame of the mirror structure, provide an inturned lip embracing the frame and provide a raised bead by which to effect a seal with the mirror window when the parts are brought into abutting relationship.

A specific object is to provide a fluid mirror construction comprising an enclosure including a transparent window, a frame for mounting the window, a flexible pre-shaped diaphragm providing a fluid chamber with the frame and window and a movable reflector operable in the fluid toward and away Ifrom the window and wherein the diaphragm is so constructed and arranged that it 3 wraps around the outer surface and the opposite ends of the frame and provides a seal between the window and the frame as well as a means of connection to the movable reflector.

Other objects and advantages of the invention will become further apparent from the following description and from the drawing wherein:

FIGURE l is a side elevational view of an adjustable rear view mirror in its bright position and embodying the features of the invention, the mirror assembly being shown in section and the support therefor partly in elevation and partly in section to more clearly show the invention.

FIGURE 2 is an end view and section taken at 2-2 of FIGURE 1.

Referring to the drawing the numeral 10 generally designates a side mounting type adjustable rear view mirror device provided with a mounting bracket 11 preferably of metal such as die-cast aluminum or brass by which it is secured to an outer side surface of a vehicle (not shown). Secured to the outer end or head 12 of the bracket 11 by screws 13 is a hood or housing 14 which has a wall 16 that surrounds the mirror assembly generally designated by the numeral 22 to protect the same from the weather. The mirror assembly 22 is preferably pivotally supported on a spherical headed hollow sleeve 24 slidably mounted in a cable guide and control mount 26. The latter comprises an enlarged head portion 28 having a. tapered stem 32 extending rearwardly into the bracket head 12 and secured in a complementary shaped bore 34 therein by a screw 36 coaxial therewith. The head portion 28 is provided with rearwardly extending cable receiving bosses 38 at three equally spaced angular positions around the circumference of the flange to provide threaded recesses 40 in which to secure by threading therein the coiled sheathing 41 of the cables 42, 44 and 46. These cables connect as seen in FIGURE 2 at corresponding positions to the mirror assembly 22 for providing a universal or swivel adjustment of the mirror assembly 22 to any angular position around the spherical pivot 24. The spherical headed sleeve 24 is biased forwardly and preferably by a conical compression spring 48 -so as to seat the same in a bearing depression 50 provided in an outward or rearward extending projection 52 of 'a support plate 54 of the mirror assembly forming a part thereof and to which further reference will hereinafter be made. An opposite balanced force is furnished to the assembly 22 by the mirror adjustment cables 42, 44, and 46 which operate in the flexible tubes or sheaths 41 and are constantly under tension and connect to a manual control means (not shown). For specific details of a suitable three-wire control such as here contemplated for making angular mirror adjustments, reference is made for example to the patent to Jacobson 2,931,245, the structure of which insofar as applicable here is adopted and made a part of this disclosure.

The mirror assembly 22 comprises in addition to the support plate S4 described above, a circular window 60, a circular metal frame 62 of L section, and a flexible diaphragm 64, the last three-named parts forming an enclosure for receiving a movable mirror or reflector generally designated by the numeral 66 and providing a fluid chamber 68 for receiving an opaque optical fluid 70 such as described in the concurrently filed application of Teague et al. entitled Optically Dense Fluid and Method of Making the Same, Serial No. 156,535. The window 60 preferably comprises a piece of clear transparent glass plate and the reflector 66 is likewise preferably a glass plate provided with a mirrored surface 72 preferably on the side thereof adjacent and facing the window 60. It will be understood that the reflector 66 may also be of optically clear glass having the mirrored surface 72 on its rearward side, i.e. the side most remote from the window 60. The mirrored surface 72 of the reflector 66 is clearly visible through the transparent glass plate window 60 and acts as the reflecting surface for the mirror assembly in the bright position of the reflector 66 such as shown in FIGURE l wherein the reflector 66 is positioned against thin stops or indexing means 76 preferably three in number and equally angularly spaced around the window 60 such that a thin film preferably in the order of 0.0005 to 0.0015 remains between the reflector and the window in this forward position of the reflector.

The bright mirrored surface 72 is preferably formed on the glass reflector by well known vaporization procedures and the thickness thereof shown in the drawing is exaggerated for the purpose of illustration. Although various metals may be used in vaporized forms to produce this mirrored surface it has been found that vacuum deposited vaporized chromium or aluminum over chromium, particularly the latter, give excellent results and are preferred. For example, when vaporized chromium is used for the mirrored surfacing 72 a ray of light entering the window 60 and striking the reflector surface 72 will be reflected with an intensity approximating 55% of that of the initial ray and the corresponding value for the bright aluminum surfacing will be much greater in the order of 70 -to 80%.

It will be noted that the reflector 66 has a predetermined diameter which is less than the inside diameter of the annular portion 78 of the frame 62 such providing an annular gap 80 between the outer edge of the reflector 66 and the casing portion 78. This gap permits the free movement of the fluid between the reflector 66 and the casing 78 when the reflector 66 is moved rearwardly in the enclosure chamber 68. In this operation the reflector 66 will generally slide on a film of the fluid in the bottom of the enclosure and will to some extent be supported by the diaphragm 64, a central portion of which 82 is suitably bonded as by a suitable cement impervious to the fluid 70 and to moisture to the rear face 84 of the reflector 66. It will be observed that the enclosure is of sufficient depth permitting displacement of the reflector 66 rearwardly a suflcient distance to satisfy the desired optical conditions of the mirror assembly which require that such a layer of fluid medium be provided between the reflector and mirror to substantially inhibit the reflection of light from the mirrored surface 72 of the reflector in the rearward or night position of this member. As described in the Platzer et al application aforesaid a movement in the order of about 0.125" has been found sufficient with a fluid medium there described and which preferably has an index of refraction comparable to that of the window 60.

As previously stated a feature of the invention is the construction of the diaphragm 64. This member is preferably molded to the form shown so that it will have shape-retaining properties while still being substantially flexible for the purposes of the invention. As shown the diaphragm 64 will be of a generally shallow pan shape having a base or body portion 88, an outel rim 90 provided with an inturned lip or flange 92 spaced from the body portion 88 the depth of the frame 78 such that it may snugly embrace and t the frame. As previously described the diaphragm 64 will be secured as by bonding with a suitable cement to the reflectorrear face 84 and in the arrangement shown a central portion 82 of the diaphragm projects forwardly of the body portion for this purpose and is connected to the body portion by a conical web 94. The lip 92 of the diaphragm 64 is also preferably provided with a raised bead 96 preferably of semicircular section which may be abutted by the window 60 to form a fluid seal between it and the window. If desired, the diaphragm may be cemented prior to assembly to the frame 78 although this has not been found necessary. As shown the support plate 54 whose periphery conforms to the periphery of the angular portion 78 of the frame 62 and diaphragm 64 is made to abut the outer surface of the diaphragm 64 and is held in abutment thereto by a retaining ring 98 which also holds the window 60 against the sealing bead 96 of the diaphragm. In this connection it will be noted that the retainer 98 has a forward inwardly sloping flange 100 which abuts a complementary shaped chamfered edge 102 of the window 60 and at the opposite end is formed with a plurality of tabs 104 (see FIGURE 2) spaced circumferentially of the retaining ring, which tabs are bent against the support plate 54 adjacent the periphery thereof to hold the entire mirror assembly 22 together while simultaneously placing the bead 96 and opposite end of the diaphragm under sufficient compression to effect a fluid seal of the assembly. It will be apparent that it is a simple matter to initially assemble the frame 62 to the diaphragm and the diaphragm to the reflector 84 and thereafter bring the window 60 in position against the sealing bead 96 of the diaphragm, slip the retaining ring 98 over the window 60 and diaphragm and bend the tabs 104 in position to secure the assembly. Such final assembly is preferably carried out with the parts submerged in the fluid medium 79 in order to fill the chamber 68 therewith. It will be apparent that this is possible without any fumbling or difficulty on the part of the assembler for as evident the parts will readily go together even though the assembly be a blind one. It will also be noted that by the described diaphragm structure only a single seal is required for the entire assembly.

As seen in FIGURES 1 and 2, the support plate S4 is preferably provided with an outwardly pressed circular rib-like portion 108 and radially outwardly pressed riblike portions 110 which connect with the outwardly pressed portion 52 previously described. These portions 108, 110 not only provide stiflening ribs for the support plate 54 but in addition provide spaces into which the diaphragm may expand when an increase in volume of the fluid medium 70 occurs during temperature changes in the fluid. It will also be seen that the dish portion 52 not only includes an inward bearing depression 50 for seating the spherical end of the sleeve 24 of the mirror mount but also provides an annular depression 112 for receiving one end of a compression spring 114 which seats over the inward projection 50 at its outer end and has its inner end bearing against a plate-like member 116 suitably secured as by cementing to the portion 82 of the diaphragm 64, to normally bias the reflector 66 to its forward position against the stops 76. The plate 116 is preferably made of metal and formed with an outward depression 118 in which is anchored the reflector actuating cable 120 as by an enlarged headed portion 122. The cable 120 extends through an opening 124 in the bearing portion 50 of the support plate, passes into the bore 126 of the sleeve 24 in which its coiled sheath 127 is threadedly secured. The cable and sheathing then extend through the bracket 11 to its ultimate position of operation, usually the dash of the vehicle. It will also be noted that the support plate 54 is provided with three outward depressions 130 located intermediate the ribs 110 in which the mirror positioning cables 42, 44 and 46 are anchored.

As will be evident from the above description the outer face of the window 6l) will provide a reflecting surface of low reflectivity which will provide the surface of greatest reflecting intensity in the night position of the reflector 66 when the latter is in its rearward or night position and the mirrored surface 72 of the reflector 66 will provide a reflecting surface of high reflectivity and the reflecting surface of greater reflecting intensity when the reflector 66 is in its forward or day position. In operation of the device as described, the mirror assembly 22 may be adjusted to any angular position by operation of the cables 42, 44 and 46, there being sufficient clearance between the outer rim of the mirror retaining member 98 and the wall 16 of the hood 14 to permit such adjustment, and shifting between day and night position of the reflector will be accomplished by applying tension to the cable 120 drawing the reflector rearwardly for obtaining the night position thereof and permitting the spring 114 to return the reflector 66 forwardly against the stops 76 for its day position.

It will be apparent that various changes and modifications may be made in the described construction without departing from the spirit and intent of the invention and all changes and modifications and equivalent constructions coming within the scope of the appended claims are contemplated.

We claim:

1. A mirror structure comprising an enclosure including a substantially transparent first plate forming a window and forward wall therefor, said first plate having a light reflecting frontal face of relatively low light reflectivity and having a rearward face within said enclosure, said enclosure also including a substantially rigid open frame member having a peripheral outer wall and having forward and rearward walls and a resilient diaphragm deflning a fluid chamber with said frame and said first plate for receiving an optically dense light attenuating fluid, a second plate within said fluid chamber and movable in the fluid therein toward and away from said first plate and means to actuate said second plate, said second plate having a light reflecting face of relatively high light reflectivity confronting said rearward face of said first plate, said second plate having a rearward side in connection with a generally central portion of said diaphragm, said diaphragm embracing said outer and said forward and rearward walls of said frame member and the portion thereof embracing the forward Wall lying intermediate said first plate and said frame and providing a fluid seal therebetween.

2. A mirror structure comprising an enclosure including a substantially transparent first plate forming a window and forward wall therefor, said first plate having a light reflecting frontal face of relatively low light reflectivity and having a rearward face within said enclosure, said enclosure also including a substantially rigid open frame and a resilient diaphragm defining a fluid chamber with said frame and said first plate for receiving an optically dense light attenuating fluid, a second plate within said fluid chamber and movable in the fluid therein toward and away from said first plate, said second plate having a light reflecting face of relatively high light reflectivity confronting said rearward face of said firstv plate, said second plate having a rearward side and said diaphragm being of a preformed pan shape and comprising a generally central body portion secured to said rearward side of said second plate and a rim portion embracing said frame, said rim portion including an inturned lip for extending intermediate said first plate and frame and means for holding said lip in fluid sealing engagement with said first plate and frame.

3. A mirror structure comprising an enclosure coniprising a substantially transparent first plate forming a window and forward wall therefor, a resilient diaphragm of preformed pan-shape adapted to form a fluid chamber with said first plate for receiving an optically dense light attenuating fluid, framing means for supporting said window and diaphragm, a second plate within said fluid chamber and movable in the fluid received therein toward and away from said first plate and means for actuating said second plate, said first plate having a light reflecting frontal face of relatively low weight reflectivity and having a rearward face within said chamber, said second plate having a light reflecting forward face of relatively high light reflectivity confronting the rearward face of said rst plate and having a rearward face, said diaphragm comprising a generally central body portion secured to said rearward face of said second plate and a rim portion including a lip for extending intermediate said first plate and a seating face provided by said framing means, and said framing means comprising means for holding said lip in fluid sealing engagement with said first plate and said seating face.

4. A mirror structure comprising an enclosure including a substantially transparent first plate forming a window and forward wall therefor, said first plate having a light reflecting frontal face of relatively low light reflectivity and having a rearward face within said enclosure, said enclosure also including a substantially rigid open frame member having a peripheral outer wall and opposite side walls and a resilient diaphragm defining a fluid chamber with said frame and said first plate for receiving an optically dense light attenuating fluid, a second plate within said fluid chamber and movable in the fluid therein toward and away from said first plate, said second plate having a light reflecting face of relatively high light refiectivity confronting said rearward face of said first plate, said second plate having a rearward side and said diaphragm being of a preformed pan shape and comprising a generally central body portion secured to said rearward side of said second plate and a rim portion embracing said frame, said rim portion including an inturned lip for extending intermediate said first plate and traine, means for holding said lip in fluid sealing engagement with said first plate and frame, resilient means internally of the enclosure biasing said second plate into a first position in juxtaposition to said first plate in which position said light reflecting face of said second plate provides light reflectivity of the greatest intensity, and means carried by said second plate by which to actuate said second plate to a second position displaced outwardly from its said juxtaposed position relative to said first plate and in which position said first plate provides light reflectivity of the greatest intensity and said fluid provides a screening layer between said plates substantially inhibiting light reflections by said light reflecting face of said second plate.

5. A mirror structure comprising an enclosure including a substantially transparent first plate forming a windown and forward wall therefor, said first plate having a light reflecting frontal face of relatively low light reflectivity and having a rearward face within said enclosure, said enclosure also including a substantially rigid circular shaped frame member of L section comprising a ring-like portion forming the leg, of the L, and a sill portion extending radially inwardly of the ring portion and forming the base of the L, a resilient diaphragm defining a fluid chamber with said frame and said first plate for receiving an optically dense light attenuating fluid, a second plate within said fluid chamber and movable in the fluid therein toward and away from said first plate within said ring portion of said frame member, said second plate having a light reflecting face of relatively high light reflectivity confronting said rearward face of said first plate, and said second plate having a rearward side, said diaphragm being of a preformed pan shape and comprising a body portion having a normally forwardly projecting central part secured to said rearward side of said second plate and a rim portion embracing said frame, said rim portion including an inturned lip for extending intermediate said first plate and frame, a support plate overlying and abutting the body portion of said diaphragm opposite the sill portion of said frame member, an annular retaining ring ernbracing said first plate, diaphram rim portion and support plate for holding said lip in fluid sealing engagement with said first plate and frame, said retaining ring including a lip portion in abutment with the frontal face of said first plate and a plurality of radially inwardly extending tabs in abutment with said support plate, a second plate operating means mounting member secured to said central part of the body portion of said diaphragm, resilient means intermediate said support plate and mounting member for normally biasing said second plate into a first position in juxtaposition to said first plate in which position said light reflecting face of said second plate provides light reflectivity of the greatest intensity, and cable means carried by said mounting member by which to actuate said second plate to a second position displaced outwardly from its said juxtaposed position relative to said first plate and in which position said first plate provides light reflectivity of the greatest intensity and said fluid provides a screening layer between said plates substantially inhibiting light reflections by said light reflecting face of said second plate.

6. A mirror structure as claimed in claim 5 wherein said support plate includes a plurality of depressions on the forward face thereof to provide pockets into which the diaphragm may extend upon an increase in volume of fluid during temperature changes of the latter.

7. A mirror structure as claimed in claim 5 including a pedestal mount for the mirror structure, spherical headed means carried by said pedestal in abutment with a forwardly depressed central portion of said support plate to provide a universal swivel Connection between said pedestal and mirror structure, a plurality of cables in connection with said support plate at points surrounding said spherical headed means by which to position said mirror structure relative to said pedestal and an opening in central portion of said support plate through which the cable means for the said second plate may extend.

References Cited by the Examiner UNITED STATES PATENTS 1,195,757 8/1916 Wertz.

2,437,642 3/ 1948 Henroteau.

2,931,245 4/1960 Jacobson 88-98 X 2,972,190 2/1961 Vissing 88--1 X 3,000,262 9/1961 Rabinow et al 88-77 JEWELL H. PEDERSEN, Primary Examiner. 

1. A MIRROR STRUCTURE COMPRISING AN ENCLOSURE INCLUDING A SUBSTANTIALLY TRANSPARENT FIRST PLATE FORMING A WINDOW AND FORWARD WALL THEREFOR, SAID FIRST PLATE HAVING A LIGHT REFLECTING FRONTAL FACE OF RELATIVELY LOW LIGHT REFLECTIVITY AND HAVING A REARWARD FACE WITHIN SAID ENCLOSURE, SAID ENCLOSURE ALSO INCLUDING A SUBSTANTIALLY RIGID OPEN FRAME MEMBER HAVING A PERIPHERAL OUTER WALL AND HAVING FORWARD AND REARWARD WALLS AND A RESILIENT DIAPHRAGM DEFINING A FLUID CHAMBER WITH SAID FRAME AND SAID FIRST PLATE FOR RECEIVING AN OPTICALLY DENSE LIGHT ATTENUATING FLUID, A SECOND PLATE WITHIN SAID FLUID CHAMBER AND MOVABLE IN THE FLUID THEREIN TOWARD AND AWAY FROM SAID FIRST PLATE AND MEANS TO ACTUATE SAID SECOND PLATE, SAID SECOND PLATE HAVING A LIGHT REFLECTING FACE OF RELATIVELY HIGH LIGHT REFLEC- 